EARLY THEORIES OF SLEEP
Balm that tames all anguish.
WORDSWORTH.
Mr. Edward Binns of London, as early as 1842, published a book called
“The Anatomy of Sleep”—with the subtitle, “The Art of Procuring Sound
and Refreshing Slumber at Will.” The subtitle makes one think of the
three-volume novels of that time, but the book is fairly concise and
worth careful review. Moreover, it is in advance of many works on sleep
both before and after. (For ancient surmises see Appendix C.)
One of the favorite medical theories of sleep is that it is caused by
fatigue, and is, therefore, purely passive in its nature. Binns did not
accept this theory. He said, “Sleep is an active and positive faculty,
not a negative and passive result of fatigue or weariness.” Some of
the more modern writers, notably Manacéïne, agree with Dr. Binns that
sleep is not the result of physical fatigue or weariness. Dr. Binns
thinks that one proof that fatigue can in no sense be said to be the
cause of sleep is that, if we prolong “the state of wakefulness after
the usual period of retiring to rest, it is more difficult to induce
sleep than if we went at the usual hour.” This is especially true of
children, yet the patient may be much more fatigued at the later hour
than at the usual bedtime.
Binns’ theory is that physiological sleep is in antagonism to
intellectual activity, being the active process of nutrition,
assimilation of food, or of the repair of the waste of the body; that
it concerns the nerve centers: that is, “the ganglionic system.” It
is a generally admitted theory that man’s activity, whether physical
or mental, “uses up” tissue and nerve force, and that it is only when
repair exceeds this waste that life is maintained at a high standard.
If the activities of life be many and varied, much sleep according to
this theory would be needed to repair the waste of force. Experience
has shown that those who live purely physical lives, doing hard manual
labor with little mental exercise, need the most sleep. Those whose
activities are mostly mental generally sleep fewer hours, though the
desire for sleep may be as intense when it comes as is that of the
manual laborer. (See Appendix, Questionnaire.)
Regarding sleep as a necessity, in itself an “active and positive
faculty,” Binns says of it that “it is the true ‘vis medicatrix
naturæ’ —the healing force of nature—to whose vigilance we are
indebted for that condition of mind and body called ‘health.’” However,
he is not an advocate of long hours of sleep for everybody. He thinks
individuals differ widely in the amount of sleep needed. He makes the
general statement that, “the lower the cerebral organs in the scale
of organization, the greater the power of sleep.” On this point all
the authorities agree, and even in our own experience we learn that.
The animals nearest to man in point of development sleep more than man
sleeps; and, among men, those who live the most sluggish mental and
emotional lives sleep longer than those whose brains are more active.
There may, of course, be exceptions to this rule, and yet those
exceptions would not disprove that there is a rule. Much depends,
says the good doctor, upon the peculiarities “of the individual; the
culture of his mind; his amusement, his food, his occupation, and the
temper with which he wooes sleep. General Elliot never slept more
than four hours out of twenty-four, and his food consisted wholly of
bread, vegetables, and water.” This seems like one more link in the
chain that binds up our habits of eating with our power to sleep.
Just as heavy eating late at night may so disturb our slumber as to
leave us practically sleepless, so general heavy eating may render us
so incapable of mental activity that sleep may take possession of
us. General Elliot’s slight need of sleep was probably due, in large
measure, to his light diet, and Dr. Binns seems to be of that opinion.
We notice that flesh-eating animals, especially serpents, gorge and
then sleep long.
A modern medical authority, Sir Henry Thompson of London, in his
book, “Diet in Relation to Age and Activity,” takes somewhat similar
ground, although careful to state that he is not “a vegetarian.” He
says: “I have been compelled by facts to accept the conclusion that
as much mischief in the form of actual disease, impaired vigor and
shortened life accrues to civilized man, so far as I have observed
in our own country and throughout almost every part of Europe, from
erroneous habits in eating as from the habitual use of alcoholic drink,
considerable as I know the evil of that to be.” [9]
[9] See chap. xxi on “Natural Living.”